Complications of Wear or Corrosion of Chrome-Cobalt Hip Implants Stephen S. Tower, M.D. Affiliated Professor UAA/ WWAMI Tower Joint Replacement Clinic www.tjrclinic.com
Disclosures Index Case of Arthroprosthetic Cobaltism 2006-2009 Author of Index Case Reports AK State Epi, Alaska Medicine, JBJS 2010 Board Member Health Watch USA No economic COI
Where are we going? 21 st Century Cures Act Reduction of level of evidence to antidotal! Past House, pending in Senate Structural FDA weaknesses. Legislated FDA weaknesses. Disregard for costs of new technology.
Marketing trumps science and value NICE Report Cemented MoP $6000 Cemented CoP $8000 Hybrid MoP $10000 Safety Un-cemented MoP $12000 And Un-cemented CoC $16000 MoM Resurfacing $10000 Value MoM THA $14000
Hip Replacement Costs USA 12K – 80K JAMA 2/2013 Retrospective Study $ 0.01 Efficacy per implant Implant Registration $50 per Safety implant And Explant Analysis 1K Value Generic Parts 5K Cost, Un-Proven parts 15K Complexity, and Complications Revision surgery 50-100K
Dr. Declan Nolan 2011
The Holy Grail of Hip Replacement Lasts Forever Instant recovery Pain free Stable No activity limits Not poison the patient
510 K Devices Antecedent Device Pre-Market Approved Devices
5 Year Revision Rates Predicate Charnley THA 1970 s 2-3% PMA Metal-on-Metal Resurfacing 15% (5x) 510K Metal-on-Metal THA 44% (22x) 510K Modular Neck THA 44% (22x)
2010 Wear of chrome-cobalt hip implants ½-1 million Americans at risk Systematic Literature Review of 2318 publications we found 25 cases of cobaltism from wear of CrCo hip implants A Systematic Review of Systemic Cobaltism after Wear or Corrosion of Chrome-Cobalt Hip Implants BD Gessner , T Steck , E Woelber, SS Tower Journal Public Safety June 2015 Open Access
2015 Taper Corrosion of CrCo Components about 2 million Americans at risk Osteolysis, Pseudotumor, Sciatica 56 YO active male, 6 years post THA. Popular non-recalled Stryker 32 mm MoP 510K hip. Osteolysis detected with surveillance XR. Minimal Metallosis and Hypercobaltemia (0.9)
Monitoring Hip Patients at Risk Blood or Urine Cobalt (PBB) • 0.2 normal, > 1.0 excess exposure (Industry) • 1 small ball Metal-on-Metal THA • 2-3 large ball Metal-on-Metal HR or THA • 2-10 APRMD, subclinical and mild cobaltism • 11-100 subclinical, mild, and moderate cobaltism • 101-300 moderate to severe cobaltism • 301-1000 extreme manifestations, DEATH (1 case) Cobalt debris from corrosion likely more toxic than that produced by abrasive wear. Urine levels generally 3-5X Blood Levels
Alaskan Rejuvenate Series Recalled Implant Taper Corrosion 30 revised of about 70 at risk Median [BCo] = 4 PPB 10 with reversible Cobaltism? Mean latency to illness 2 years Mean latency to revision 3 years Population at risk systematically screened
Alaskan Revised MoM Series Metal-on-Metal Wear 35 revised of < 100 at risk Median [BCo] = 40 PPB 10 with reversible Cobaltism? Mean latency to illness 2 years Mean latency to revision 3 years Patients not systematically screened
Alaskan Non-Rejuvenate Series Taper Corrosion 6 revised of about 1000 at risk Median [BCo] = 4 PPB 5 with reversible Cobaltism? Mean latency to illness 5 years Mean latency to revision 7 years Population at risk not systematically screened
Cobaltism Awareness: Systematic Monitoring of Patients with MoM Hips Indicated 40 y/o nurse, missed 2 annual follow-ups but saw surgeon socially 1-2 times a week [BCo] = 63 ppb Reversible Neurocobaltism with 48 510K Device months of surplus Not recalled morbidity
Cobaltism Awareness: Cobaltism may precede Hip Symptoms 46 y/o Pilot F/H PD 2009 Biomet “Magnum” MoM Hips 42 months max DBS & Drugs Onset of hip pain B[Co] = 116 PPB Hips Revised to Ceramic-on-Plastic 2 months post revision B[Co] = 0.7 12 months post-op off DBS & Drugs 2 years post-op off Drugs, lowest 510K Device DBS setting Not recalled
Cobaltism Awareness: Systematic Monitoring of Patients at Risk for Taper Corrosion Indicated Rejuvenate Implanted 8/2010 20 months later: progressive fatigue, poor sleep, nausea, weight loss from 140 to120 pounds, deafness, myalgia, cognitive decline, arrhythmia and diastolic dysfunction 510K B[Co] = 11 PPB RECALL Recalled 7/2012 (at 23 months) Explanted after 33 months
Population at risk 2 million 56 y/o male: 6 and 3 years s/p 32 mm CrCo-on-Plastic non-Rejuvenate Stryker Hips Several months left groin pain: [BCo] = 4 PPB Admitted to CCU post screening ECHO for acute asymptomatic proximal aortic dissection Popular 510K MoP Hip Not known to be at risk Stryker Accolade
Metal-on-Plastic Bearing Chrome-Cobalt modular ball on Ti Alloy Stem 510K Device Zimmer MLT Stem 32 mm CrCo Head Metal-on-Plastic 66 year-old attorney, 4 months of left groin pain 8 years post implant, [BCo] of 4 PPB
A Systematic Review of Systemic Cobaltism after Wear or Corrosion of Chrome-Cobalt Hip Implants BD Gessner , T Steck , E Woelber, SS Tower Journal Public Safety June 2015 Open Access 25 Cases Identified Toxic Progeria 84% Hip Symptoms 75% cranial or peripheral nerve dysfunction 72% diastolic or systolic cardiomyopathy 72% constitutional decline 32% mood or cognitive dysfunction 48% thyropathy Mean BCo 324 (20-1000) Illness Severity correlated with BCo Reversibility Noted in non-fatal cases
Periprosthetic Consequences of Chrome-Cobalt Metallosis Pseudotumors and Necrosis of Capsule, Tendons and Bone leading to Hip Instability Weakness Prosthetic loosening can be Painful or Painless
New Hips: 1980-2010 Evolution Larger Heads More Parts Unproved material Unproved design Unanticipated modes of failure Science or Marketing Driven?
Complications of Hip Implant Chrome-Cobalt Wear & Corrosion Unexpected Long Latency Significant
What went Wrong? • Conflict of Interest? • Premarket • Market • Regulation • Professional spheres • Post Market
Cost of Metal-Metal Debacle USA A Billion Dollars per year Design Surgeons of the ASR paid about $20 Million Cost of 510K Debacle USA? Ten Billion Dollars per year For non-recalled Hips Companies profit from sale of both primary and revision Implants
Monitoring Patients with at-risk hips for hip tissue complications Annual Blood or Urine Cobalt Level • > 1 (3) some wear or corrosion likely • > 3 (9) increasing risk of problems cross-sectional imaging even if no symptoms at hip. Hip Symptoms ( regardless of Cobalt levels) • Plain Radiographs • Cross-sectional imaging
Monitoring Patients with at-risk hips for Cobaltism Annual Blood or Urine Cobalt Level • > 1 (3) some wear or corrosion likely • > 3 (9) increasing risk of problems cross-sectional imaging even if no symptoms at hip. • Through neurologic, cardio-vascular, psychiatric, and constitutional ROS. Positive ROS for Cobaltism • Base-line audiogram, echocardiogram. • Neuro-cognitive testing
Treatment of patients with Hypercobaltemia, Cobaltism, or Hip Complications Blood cobalt 3-10 no symptoms • Baseline cross-sectional imaging of the hip • Baseline audiogram, echocardiogram. • Baseline neurocognitive testing • Every 6 months repeat neurologic, cardio-vascular, psychiatric, and constitutional ROS and urine and whole blood cobalt level. Blood cobalt > 10 or Cobaltism or Tissue Damage at the Hip • Consider Revision Surgery if patient fit of major operative procedure • Chelation might be considered if patient is unfit for major surgery
Cost Explant Analysis 1-2K
Hip Replacement Costs USA 12K – 120K JAMA 2/2013 Retrospective Study $ 0.01 per Efficacy implant Safety Implant Registration $50 per And implant Value Explant Analysis 1-2K per Explant Generic Parts 5K Cost, Complexity, New unproven expensive implants and 10-20K premium leads to Complications Revision Surgery 50-150K
Where are we going? • 21 st Century Cures Act • Reduction of level of evidence to antidotal • Past House, pending in Senate • Structural FDA weaknesses. • Legislated FDA weaknesses. • Disregard for costs of new technology.
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